In this context, FIG. 1 shows a conventional circuit arrangement 10 which can be coupled via an input with input connections E1, E2 to an AC supply voltage UN. Downstream of the input E1, E2 is a rectifier 12. The series circuit including three light emitting diode (LED) chains LK1, LK2, LK3 and a driver apparatus 14 for the LEDs in the LED chains LK1, LK2, LK3 is coupled between the output connections GA1, GA2 of said rectifier. Each LED chain is connected in parallel with a capacitor, i.e. the LED chain LK1 with the capacitor C1, the LED chain LK2 with the capacitor C2 and the LED chain LK3 with the capacitor C3. Of course the circuit arrangement can have any desired number n of parallel circuits including LED chains and capacitors.
The capacitors serve the purpose of positively influencing the modulation response of the LEDs, in particular of reducing flicker. Furthermore, the line power factor can thus likewise be positively influenced since, in the phases in which the voltage present across the series circuit including the LED chains is lower than the required LED chain voltage, the LEDs are supplied from the capacitors. The electronic components are generally arranged on a printed circuit board, which is then accommodated in a luminaire housing.
The electronic components are generally arranged on a printed circuit board, which is then accommodated in a luminaire housing.
The abovementioned structures may, however, have the disadvantage that the housing of such a light source needs to be provided with larger dimensions owing to the capacitors which are to be connected in parallel with the LED chains and light sources with such large form factors are then no longer suitable for specific intended uses. In particular for lighting poorly accessible areas, form factors which are as low as possible are desirable. This may apply also for applications in which the light source is intended to be as movable as possible in order for example to be able to be used manually by a user for illuminating poorly accessible areas.